What should be the maximum number of lighting fixtures connected to a 20-amp circuit?

To determine the maximum number of lighting fixtures that can be connected to a 20-amp circuit, it is important to consider the electrical load and general code guidelines. A 20-amp circuit can typically supply 2400 watts of power (20 amps x 120 volts).

When installing lighting fixtures, a common rule of thumb is to allocate approximately 180 watts of load per 15-amp circuit, which includes a safety factor. Therefore, for a 20-amp circuit, it’s reasonable to consider a maximum load of around 2400 watts. Given that most typical lighting fixtures (using standard incandescent bulbs) use about 60 watts each, you can divide the total wattage by the wattage per fixture to get the maximum number of fixtures.

Thus, with a total of 2400 watts available on a 20-amp circuit, dividing this by 180 watts (assuming 180 watts as a more conservative estimation to allow for safety and other loads) gives about 13 fixtures. This guideline aligns closest with 12 fixtures in practice, because it's always prudent to slightly reduce the count to ensure safety and to account for the potential additional load from various characteristics of fixtures or connected devices.

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